stick with regular BBs. while Bioval BBs are good performers, recent controversy has made them blacklisted at many games. If you cant get any bastard BBs and you want heavier than .25 (from metal tech), than get KSC bbs, or Madbull. Here is my take with the bb companies in terms of product quality:
Best BBs hands down. They are the bread and butter of Canadian airsofters. Unsurpassed in terms of quality and performance. They are the industry standard for Canada
Excellent BBs at a great price. They come in a variety of weights and i have heard of no one having performance issues with them.
In terms of quality, these are very good, but they lack product diversity, with their heaviest weight being .25g only.
A solid choice due to their variety. Easily the most diversified brand of BBs, with extreme heavy-weights for snipers, to bio bbs, to tracer bbs. they have a need met for all forms of airsofting with a price that can't be beat. However, their quality is lacking somewhat on some of their new products. i have heard reports of people having misfeeds and some of their heavier bbs are coated with oil that can rub off (see Construction Paper Test) and gunk of inner barrels and mags. Still, i plan on using their tracer BBs cause they come in .25s. Most companies Make .2g tracers only.
In terms of performance, they are excellent, but due to recent controversy around them, most game hosts ban them from games. i wont go into the details on it, as there are numerous, multi-page threads regarding the issue, but just keep that in mind. no point having bbs if you cant use them at a game.
ultimately the choice is up to you, but i hope this little comparison helps you out.